Radiator upgrade question

I wanted to upgrade the cooling system on my 69 roadrunner runing a 383. As of now i have the stock 22 inch version but after a lot of reserch i think the best idea is to enlarge the opening and put in a 26 inch radiator in it's place.

I am looking for a driect fit 26 unit and the shroud so any advice on where to get them that is a resonable price?
Thanks
Stu

Are you having a cooling problem? If not, I would leave it alone.

If so, you can do what I did. Install a 26" Champion 2 row aluminum radiator in the existing 22" support. I didn't want to hack my nice support so I just spaced the rad out from the support a little so the air can get to the entire core. It worked perfect for me.




I think I paid around $200 for the radiator.

I wouldn't cut the opening out to 26 inches.Get a 22" Champion like the one pictured above. I put a 22" 3 core in my car like the one pictured above and it works great. My car never ran so cool.

I agree. I got a 4 core Champion a few weeks back for the 69 Dart. It was only a 22" core support so I stayed with the 22" and added more cores. This was a direct fit to the radiator support with no modifications required.

Thanks for the advice and i will look into the Champion radiators, but i see no fan shroud in the photos. I thought you should always run a shroud for optium cooling??


Stu

Yes, definitely use a shroud. Use a clutch drive if aren't already. You might also look into getting a 3rd row in your radiator if possible. tanks look big enough. it's not as good as having more width, but it does help. and I agree on not cutting, don't think you have to. be creative, and it's a good feeling when you don't have to cut

Stu I just put this in a little over a week ago. I haven't made it to the shroud stage yet. I may see how it does without one and if its not needed I may not run one.

I don't run a shroud. It doesn't need it but yes, it's a good idea to have one regardless.

I don't have a shroud or a clutch fan. The radiator is drilled and tapped for a shroud though.

The engine does not overheat at all in my own area of San Francisco where temps usually stay around 50 to 70 degress.

The issue is when i am away from the area and stopped just ideling in traffic on a very hot day. Then within minutes the temp climbs and the coolant boils over. On the freeway no matter how hot it gets i have no problems as long a i am moving at a good clip.


Here's what i have done:

Radiator has been hot tanked and all leaks repaired, i am running straight distilled water with an additive for the pump, I have a 17 lb cap, a nice new HD clutch fan and a high flow water pump.

classic problem. I think a shroud would help that a lot.. but obviously so would more capacity. how many rows in the radiator - 2?

How crafty are you? There are many options. Like was already mentioned, you could do a wider aluminum unit, offset it like shown above (which is a very elegant solution). I'd couple it with a shroud.

you could get a third row added to your stock radiator if can fit another row, and if you don't already have it. Again, couple with shroud.

You might also test the clutch drive - I've seen them bad right out of the box, especially if they are old were stored improperly (they can leak the fluid)

Are you running a thermostat (you should be)? What temp?

You could always buy an aux electric fan and mount it in front of the current setup. a simple switch could turn it on for you (or you could make it automatic with enough ingenuity). that'd be a huge help at idle when there is minimum airflow across the fins

don't forget - in a bind, roll down the windows and blast the heater. that can save the engine and bring the temps down. I've been there.. sure aint fun in the summer.

My father once routed a spare heater core in the front of his 64 413 New Yorker, which was prone to overheating. he plumbed it in via the heater hoses, and he said it never overheated again. sometimes you just need a bit more capacity. that's not very pretty though...

Which fan are you using? You want the 7 blade one

For slow speed cooling problems you need to either speed up the water flow, increase capacity or increase the air volume being pulled through the radiator...or a combination of those.

I had this exact problem. I switched to a 26" radiator and it helped a little but not much. I installed a 18" mechanical nylon fan and smaller water pump pulley to speed up the water flow and now it's good now. I had to space out the pulley a little to clear the water pump bolts though.

Im very happy with my 22 in radiator from Mancini Muscle Car Aluminum Radiators and it works fine even to my 505 stroker ! These are made to bolt right in and no hassel or drilling and hose fittings as stock but you need to mesiure and fill out a order form first

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The issue is when i am away from the area and stopped just ideling in traffic on a very hot day. Then within minutes the temp climbs and the coolant boils over. On the freeway no matter how hot it gets i have no problems as long a i am moving at a good clip.

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Even after a boil out the OE cruddy rad may not be flowing enough to compensate for the lesser amt of air & water flow at lower speeds. I'd add a shroud & a smaller dia WP pulley & if that dont do it (& I suspect it wont) then as said a 3 or 4 row Champion. I have one ( 2 row) on a DD 318 & cools well tho cooling ain't an issue in my app & no leaks & just had to redrill 1 mounting hole which ain't nothing. Holler how it turns out/what fixes it for you. With it boiling over as you described there's definitely a serious problem